Movable bolster for presses



Feb. 1a, 1969 A. MICHELSQQN 3,427,854

MOVABLE BOLSTER FOR PRESSES EN M40 FIG 2 2f 2g M20 FIG. 3

INVENTOR. ANATOL. MICHELSON BY Ww f f@ ATTO` NEYS.

Sheet INVENTOR. ANATOL. M ICH E LSON lwm ATTORNEYS.

Feb. 18,` 1969 A. MICHELsoN MOVABLE BOLSTER FOR PRESSES Filed March 28, 1967 United States Patent O 3,427,854 MOVABLE BO STER FOR PRESSES Anatol Michelson, Glenolden, Pa., assignor to E. W. Bliss Company, Canton, Ohio, a corporation of Delaware Filed Mar. 2s, 1967, ser. No. 626,460 U.S. Cl. 72-448 8 Claims Int. Cl. B21j 13/00; B30b 15/02, 15/06 ABSTRACT OF THE DISCLOSURE A movable press bolster arrangement especially suited for die changing in metal working presses. The arrangement includes a carrier or bolster provided with wheels which permit it to be rolled into and out of the press. In order to relieve the load from the wheels and permit the carrier to remain in the press during press opera tion, cooperating inclined surfaces are provided on the carrier and the press bed. The surfaces are arranged so that as the carrier is moved toward a linal position in the press, the surfaces engage and further movement of the carrier causes it to move up the surface on the bed to thereby relieve the load from the wheels.

The present invention is directed to the press art and more particularly to an improved movable bolster arangement.

The invention is especially suited for use in changing dies in metal forming presses and it will be described with particular reference thereto; however, it is appreciated the invention is capable of broader applications and could be used wherever it is desired to leave a material or die carrier in position in a press during press operation.

In the press art it is common practice to provide metal working presses with movable bolster arrangements to facilitate changing die sets. In general, these arrangements have comprised sets of tracks or guideways which extend from a position exterior of the press into and across the press bed. A wheeled carrier was mounted for movement into and out of the press on the tracks. When it was desired to move a die set into position in the press, the die set was mounted on the carrier while it was outside the press. The carrier was then rolled along the tracks into position in the press. Once in the press, mechanism functioned to bring the bottom of the carrier into engagement with the press bed so that during subsequent press operation, the impact loads on the dies would not act on the wheels of the carrier, but rather, would be transmitted directly from the carrier to the bed. Additionally, a separate mechanism was provided to firmly clamp the carrier into engagement with the press bed.

In general, two different arrangements were utilized for binging the bottom of the carrier into engagement with the press bed. The rst of these arrangements comprised providing lowerable tracks or track sections in the press bed. The carrier was rolled into the press and the tracks subsequently lowered to bring the carrier down against the bed. The second arrangement cornprised providing the carrier with wheels that were movable between raised and lowered positions. When the carrier was in position in the press, the wheels were actuated to a raised position thus permitting the carrier to lower against the bed.

Both of the noted arrangements were, however, quite complex and required a substantial amount of mechanism to be built into the press bed or the carrier. Additionally, in both of the noted arrangements separate clamping mechanisms were also required to be built into the press 3,427,854 Patented Feb. 18, 1969 bed. As a consequence, initial cost, as well as maintenance cost on presses using these arrangements was high.

The present invention provides a highly simplified moving bolster arrangement which does not require complex track lowering or wheel raising mechanisms. Additionally, because of the unique arrangement of the invention it is not necessary to provide any separate clamping mechanisms in the press bed.

In accordance with the present invention an improved movable carrier arrangement is provided for a power press having a bed, a ram movable vertically toward and away from the bed, and a carrier having members on which it is supported for movement in a rst direction from a position outside the press to a second position in the press. The improvement comprises means for moving the carrier in the first direction from the second position to a third located position within the press wherein the Weight of the carrier is relieved from the mems bers, the means include: iirst means carried by the carrier and defining a lirst downwardly facing surface which is upwardly inclined in the first direction, second means supported by the bed and deiining a second upwardly facing surface upwardly inclined in the first direction, the first and second surfaces are aranged so as to come into engagement as the carrier is moved in the rst direction from the second to the third position, and power means for applying to the carrier a force having a cornponent acting in the iirst direction to thereby move the carrier up the `first surface and relieve the load from the members.

In accordance with a more limited aspect of the invention cooperating clamp members extend upwardly from the bed for engagement by cooperating clamp members which extend downwardly from the carrier so that as the carrier is moved into its third position it is simul taneously clamped to the press bed.

By providing the inclined cooperating surfaces on the press bed and the carrier the necessity of complex track lowering or wheel raising mechanisms is eliminated, and the carrier is brought to its final located position through the use of a single power means.

Accordingly, it is a primary object of the present invention to provide a highly simplified movable bolster arrangement.

An additional object of the present invention is to provide a movable bolster arrangement in which the nal positioning of the bolster is accomplished by a single power means.

A further object of the present invention is to provide a movable bolster arrangement in which the clamping and locating of the bolster is accomplished simultaneously -with the movement of the bolster into the located position in the press.

These and other objects and advantages will become apparent from the following description used to illustrate a preferred embodiment of the invention when read in conjunction with the accompanying drawings wherein:

-FIGURE 1 is an elevational View, somewhat diagrammatic, of a press having a movable bolster arrangement constructed in accordance with the present invention;

FIGURE 2 is an enlarged elevational view showing the movable bolster immediately prior to being moved into its final position in the press;

FIGURE 3 is an enlarged elevational view showing the bolster in its located position in the press, and

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 3.

Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting salme, FIGURE 1 shows the overall arrangement of a metal -fworking press A provided with a movable bolster assembly B constructed in accordance with a preferred embodiment of the present invention.

The precise arrangement and construction of press A is not important to the present invention. However, as shown in FIGURE 1 the press comprises a bed 10 provided with four vertically extending uprights 12 which carry an upper ram 1'4 mounted for vertical reciprocation toward and away from the bed 10. Conventional drive means, not shown, are provided to drive the ram. G-uideway forming members in the form of tracks 16 extend from a position exteriorly of the press into and across the press bed. These tracks provide means for guiding the movement of the bolster or carrier into and out of the press.

Of particular importance to the present invention is the arrangement of movable bolster assembly B. As shown in FIGURES 1 through 4, this assembly comprises a bolster or carrier having a main frame 20 provided with support members shown in the form of wheels 22 which are carried by brackets 24 extending downwardly from frame 20. As shown in FIGURE 1, the carrier is adapted to be moved from a position exteriorly of the press, such as shown by dotted lines, to a fixed located position within the press and beneath the ram 14. This permits a die set 21 to be positioned in mated relation on the carrier while it is outside the press and the lower die half 2lb connected to the carrier such as by bolting, and then moved into the press to a position beneath the ram. -At this time the ram can be actuated downwardly and the upper die half 21a connected thereto such as by bolting or clamping.

In order that the carrier may remain in the press during the press operation, means are provided to relieve the load from the support wheels and provide a firm foundation for the carrier. As previously discussed, in the past this has been accomplished by providing lowerable tracks or by providing the carrier with wheel raising mechanisms. Both of these prior arrangements however, are undesirable because of the complex mechanisms which must be built into the press bed or the carrier. The present invention however, utilizes an extremely simple arrangement which obviates the necessity of special raising and lowering mechanisms. In accordance with the invention, this arrangement comprises a rst member 26 Iwhich is carried by the press bed and has an upwardly facing surface 28 which is upwardly inclined to the left as viewed in FIGURES 2 and 3. A second similarly shaped member 30 is carried by the bottom of frame 20. Member 30 has a downwardly facing surface 32 which is upwardly inclined to the left as viewed in FIGURES 2 and 3. Surfaces 28 and 32 are arranged so that as the carrier is moved into the press the surfaces will come into engagement a short distance prior to the carrier reaching its final located position in the press.

As can be seen, with the members 26 and 30 arranged in the described manner, the final movement of the carrier to the left causes it to be -moved up surface 32 to thereby move Iwheels 22 a slight distance up and away from the tracks 16. In this manner, all of the impact load acting on the carrier during the press operation will be borne by the members 30 and 26 and none transmitted to the wheels.

Although it is apparent that the angle of inclination of surfaces 32 and 28 could theoretically be substantially any angle, it can be seen that the larger the angle, the greater the component of force acting to move the carrier to the right in response to contact by the press ram. For this reason, the angle of inclination of the surfaces 32 and 28 is preferably substantially below the magnitude of the friction angle for the combination of materials used for forming members 26 and 30. Thus, in this regard, the surfaces act as horizontal surfaces and no eiiective horizontal components of force are generated. In the preferred embodiment members 26 and 30 are formed from steel and the surfaces 28 and 32 are relatively smooth and well polished. For a combination of steel and steel the friction angle would be somewhere in the range of from 6-8 degrees and the angle of inclination of the surfaces would preferably be in the range of from 1.5 to 2. It is understood, of course, that the most desirable angles would vary substantially depending upon the particular materials used and their surface finish.

A variety of means could be used to move the carrier up surface 32; however, according to the preferred embodiment the means used comprise a transversely extending pusher roller 34 which is carried at the end of a pair of arms 36 pivotally mounted on brackets 38 carried in the press bed. As can be seen in FIGURES 2 and 3, roller 34 is arranged so that as the arms are rotated to the left the roller enters a transversely extending slot 40 formed in the right hand end of member 30. Consequently, as the arms are rotated to the left the roller acts against the left hand side of slot 40 and exerts a force which causes the carrier to be moved up surface 32. Although many types of power means could be utilized for oscillating arms 36, the particular means shown comprise a hydraulic screw jack `42 which is pivotally mounted by a bracket 44 carried in the press bed or the press room floor. The screw shaft 46 of jack 42 is connected by a bracket 48 which is pivotally connected to the push roller 34. Preferably the jack 42 is of the self-locking type.

Many types of means could be used to locate and clamp the carrier in position under the ram. However, the present invention provides a unique locating and clamping arrangement which is preferred. As shown in the drawings, this arrangement includes a first pair of clamp members 50 which are positioned on the left hand end of the bed and a second pair of clamp members 52 which are positioned on the right hand end of the bed. Members 50 and 52 have downwardly facing inclined wedge surfaces 51 and 53 respectively. `Preferably the wedge surfaces .a-re inclined in the range of from 25 to 45 from the horizontal. A second pair of cooperating clamp members 56 and 58 are connected to member 30 and are provided with upwardly facing wedge surfaces 57 and 59 respectively. These surfaces are inclined at substantially the same angle as surfaces 53 and 51. As can be seen, as the carrier is moved into position up the surface 32 the clamp members engage, and thus, limit further movement of the carrier to the left while sirnultaneously clamping it in position on the surface 32. Because of the self-locking nature of the jack 42 the carrier is thus firmly positioned and cla-mped to the bed. Additionally, because the inclination of surfaces 28 and 32 is below the friction angle the force which must be exerted by the jack is not especially large. However, it is understood that should the angle be increased, a substantially larger force would be required to maintain the carrier in position.

To remove the carrier from the press it is only necessary to actuate the hydraulic jack 42 to retract the screw shaft 46 and swing the arms 36 and roller 34 to the right. As roller 34 moves to the right it contacts the right hand surface of slot 40 and exerts the force necessary to move the carrier down the inclined surface 32 until the wheels 22 come into engagement with tracks 16. Further movement of the arms 36 to the right causes the roller to be moved to the position shown in FIGURE 2. The carrier can then be rolled out on tracks 16 and a new carrier and die set rolled into the press.

As can be seen, the bolster assembly of the present invention is extremely simple in construction and permits a single power actuator to move the bolster into position and simultaneously exert the necessary clamping force.

The invention has been described in great detail suiiicient to enable one of ordinary skill in the press art to practice the same. Obviously modifications and alterations of the preferred embodiment will occur to others upon a reading and understanding of the specification and it is my intention to include all such modifications and alterations as part of my invention insofar as they come within the scope of the appended claims.

Having thus described my invention, I claim:

1. In a power press having a bed, a ram movable vertically toward and away from said bed and a carrier having members on which it is supported for movement in a first direction from a position outside the press to a second position in said press, the improvement comprising: means for moving said carrier in said first direction from said second positon to a third position Within said press wherein the weight of said carrier is relieved from said members, said means including: first means carried by said carrier and defining a first downwardly facing surface which is upwardly inclined in said first direction, second means supported by said bed and defining `a second upwardly facing surface upwardly inclined in said first direction, said first and second surfaces being arranged so as to come into engagement as said carrier is moved in said first direction from said second to said third position, and power means for applying to said carrier a force having a component acting in said first direction to move said carrier up said first surface to thereby relieve the load of said carrier from said members.

2. The improvement as defined in claim 1 wherein said first and second surfaces are inclined from the horizontal by an angle less than the friction angle for the materials from which they are formed.

3. The improvement as defined in claim 1 including first clamp means carried by said bed and second clamp means carried by said carrier, said first and second clamp means being arranged to come into clamping engagement as said carrier is moved from said second to said third position.

4. The improvement as defined in claim 3 wherein said first and second clamp means comprise cooperating wedge members fixedly connected to said bed and carrier respectively.

S. The improvement as defined in claim 1 wherein said power means includes a pivotally mounted member selectively engageable with said carrier.

6. The improvement as defined in claim 1 wherein said first and second surfaces are inclined at an angle of less than ten degrees from the horizontal.

7. The improvement as defined in. claim 1 including clamp means for simultaneously locating and clamping said carrier in said third position.

8. The improvement as defined in claim 7 wherein said clamp means comprise cooperating first and second wedge members carried by said carrier and said bed respectively.

References Cited UNITED STATES PATENTS 2,908,405 10/1959 Logan 1D0-299 2,988,234 6/1961 Barothy 10C-299 2,996,025 8/1961 Georgef 100-299 3,212,430 10/1965 Clements 100-299 3,368,479 2/ 1968 Gregorovich 100-229 CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner.

U.S. Cl. X.R. 

